Burner construction



Dec. 31, 1968 w. R. DIRK ETAL 3,

BURNER CONSTRUCTION Filed April 27, 1967 sh t FIGI INVENTORS WILLIAM R. DIRK 8a CLIFFORD D. PETERSON 2 BY QWWATTORNEYS.

Dec. 31, 1968 w. R. DIRK ETAL 3, 3

BURNER CONSTRUCTION Filed April 2'7, 1967 sheet 2 FIGZ INVENTORS WILLIAM R. DIRK 8: CLIFFORD D. PETERSON BY w M YWMTTQRNEYS.

United States Patent 6 3,419,338 BURNER CONSTRUCTION William R. Dirk and Clifiord D. Peterson, Marsllalltown, Iowa, assignors to Lennox Industries Inc., a corporation of Iowa Filed Apr. 27, 1967, Ser. No. 634,375 Claims. (Cl. 431181) ABSTRACT OF THE DISCLOSURE An improved burner for use in a gas-fired furnace having a W-shaped internal configuration when viewed in cross-section that decreases the operational noise level on ignition and combustion as compared with conventional cone-type burners and which is less sensitive to manufacturing tolerances. The burner is comprised of a pair of adjacent V-shaped recesses defined by outwardly diverging perforated walls. Air enters the recesses through the perforations in the walls. Fuel enters the apex of each recess and is distributed along the length of each recess for mixture with air.

Background and summary of the invention A conventional type of burner used in gas-fired furnaces is the cone-type. Fuel is introduced in the small end of the cone or funnel, and air for combustion is introduced adjacent the small end of the cone. A suitable electrode is provided for igniting the fuel and a sensor may be provided to control the flow of fuel to the burner. A disadvantage of such cone-type burners is that at reduced heating rates, excess air is provided at the burning point, thus adversely affecting the combustion process.

The present invention is concerned with a novel gas burner comprising housing means defining a box-like member having substantial length and width wit-h respect to the height thereof. Perforated plates are disposed in the housing so as to define a W configuration or a pair of adjacent V-shaped recesses. A gas inlet opening is provided at the apex of each V-shaped recess for supplying gas separately to each recess. Fan means communicate with an air inlet in the housing means for supplying air to the perforations in the plates for mixture with the fuel supplied to recesses.

The novel gas burner assembly of the present invention is far less sensitive to manufacturing tolerances than a cone-type burner construction. The device of the invention decreases the operational noise level on both ignition and during combustion. The air required for com.- bustion may be delivered at less total static pressure than a cone-type burner, since the air forced into the novel burner provides more free area for air flow. As gas is supplied separately to each chamber within the housing of the gas burner assembly, the air-gas mixture for combustion in one chamber is not influenced by that in the other chamber and near perfect combustion may be obtained utilizing natural gas, LP gas and air, or straight LP gas.

Brief description of the drawing The invention will be particularly pointed out in clear, concise and exact terms in conjunction with the accompanying drawing of the invention in which:

FIG. 1 is a partial cross-sectional view of a gas furnace embodying the burner assembly of the present invention;

FIG. 2 is a rear elevation view of the novel burner assembly including the blower fan secured thereto;

FIG. 3 is a front perspective view of the burner assembly;

FIG. 4 is a front perspective view of the burner as- Patented Dec. 31, 1968 the burner assembly.

Description of the preferred embodiment Referring now to FIG. 1, there is shown a gas furnace 10 embodying the burner assembly of the present invention. The gas furnace 10 comprises a box-like housing or cabinet 12 having an open front closed by removable access panels 13 (only one of which is shown). In the lower portion of the cabinet is an inlet (not shown) communicating with the return air duct from the area to be treated. The outlet 16 in the cabinet 12 communicates with the duct for forwarding treated air to the area to be conditioned.

Provided within the furnace 10 is a blower 18 for circulating air through the cabinet 12 and over the heat exchanger 20. The blower 18 illustrated comprises a centrifugal fan disposed within a scroll aflixed to the cabinet 12.

The heat exchanger 20 is of the type best shown and described in the co-pending application of William R. Dirk et al. Ser. No. 534,499, and reference may be had thereto for a more complete and detailed explanation. Essentially, the heat exchanger 20 comprises a plurality of elongated tubes 22 disposed about an enlarged central tube or cylinder 24, with the tubes 22 being affixed at one end to front breeching 26 and at the other end to rear breeching 28. The central tube 24 is joined to the rear breeching 28 and is connected to the vestibule panel 30, but not to the front breeching 26.

Secured to the vestibule panel 30 is the burner assembly 34 of the present invention. The burner assembly comprises a housing 36 to which is secured a combustion air fan or blower means 38. Combustion air supplied to the interior of housing 36 is discharged through a plurality of perforations in the forward portion of housing 36 as will be more fully explained hereafter. The combustion air discharging through the openings or perforations 40 in the housing mixes with the gas supplied from the gas inlets 68 to effect the proper combustion thereof. The gases burned within the burner tube 24 pass into the rear breeching 28 and then back through the tubes 22 to the annular front breeching 26. The flue products of combustion then pass through the opening 48 into a diverter 50. The diverter 50 is a box-like member with an outlet for flue gas discharge duct 52 and a relief opening 54 which matches or aligns with the opening in panel 13. The flue gases discharge through duct 52 to communicate with the flue conduit for discharging flue gases to the atmosphere. A flue bafile 49 may be provided in the outlet opening 48 to restrict the flow of combustion gases to establish proper combustion within the heat exchanger.

Referring more particularly to FIGS. 2-5, there is better illustrated details of construction of the novel burner assembly. The burner assembly 34 comprises a housing 36 to which is directly secured a combustion air fan or blower means 38. The blower means 38 include a motor 39 affixed to a blower 37 for drawing air into the blower housing and discharging the same into an internal passage within the housing 36. A divider or air splitter may be disposed within the housing 36 for separating the air into two air streams so as to facilitate more uniform entry of the air into the chambers disposed between the plates 42 and the housing 36, thereby providing more even air distribution into the generally V- shaped recesses defined by the plate means 42, which diverge from one another outwardly from the housing and end walls 43. The plate means may be separate members or may be formed from a single member suitably shaped to define a pair of adjacent generally V-shaped members or a W member as seen in FIG. 4. A mounting plate 35 is secured to the housing 36 for mounting the burner assembly in a furnace.

Gaseous fuel is introduced into the apex end of each generally V-shaped recessed portion, indicated generally by the numeral 66, through conduits or gas inlets 68 which are connected to a conduit communicating with a suitable source of gas, as for example, natural gas commonly used for residential heating purposes, or liquefied petroleum gas. Suitable control means 70 (FIG. 3) are provided for permitting flow of gas to one or both of the gas inlets so as to permit staging of the burner operation.

Disposed within the housing 36 adjacent each inlet 68 is an elongated orifice plate member 72. The orifice plate members 72 are co-extensive with the length of the plate means 42 and are provided with orifices so as to permit the discharge of gas into the V-shaped recessed areas along the length of the plate 42. An imperforate gas distributor plate 73 is disposed adjacent to the orifice plate member 72. The distributor plate is co-extensive in length with the orifice plate member 72 and is of a width less than the spacing between the adjacent plates 42 to provide narrow slot-like openings 71 between the flanged ends of plate 73 and the adjacent Wall 42.

Air ports or openings 41 may be provided to direct air outwardly at right angles from the plane of the face of the burner assembly, The air jets issuing from openings 41 would assist in completing the burning process and would maintain separation between the combustion processes occurring in each of the generally V-shaped recesses 66.

The gas is ignited in a conventional manner by means of a sparkplug electrode 74 which is suitably secured to the housing 36. A flame protector sensor 76 is provided and is secured in an electrical circuit with the sparkplug electrode 74 in a conventional manner.

It will be observed that air enters the housing 36 only through the passage in the housing communicating with blower 37 for discharge into the chamber 67 defined between the interior of the plate means 42 and the interior of the housing means 36. If desired, a damper 75 may be provided to control flow of air through the passage into housing 36. A plurality of openings 40 are provided in the plate 42 over the entire surface thereof so as permit introduction of the combustion air in a positive manner into the generally V-shaped recessed portions 66. Gases discharged through the openings in the orifice plate member 72 at the apex of the V-shaped recesses 65 are spread to the sides along the walls or plates 42 hv the gas distribution plate 73 to enhance mixture with tl air so as to provide for efficient burning of the gas.

The invention utilizes 100 percent secondary air; that is, all the combustion air is introduced into the V-shaperl recessed portions 66 of the plate means 42 through th openings 40 for mixture with the fuel discharging from the openings in the plate 72 communicating with th chambers 71 within elongated channels 69, which defin the ends of the generally V-shaped recesses 66. Combustion air mixes with the gas adjacent the walls 42 and burns quickly, without an elongated burner flame.

The electrical ignition system may be of conventional design and may include a solid state flame ignitor, flame sensor, limit controls, and other electrical devices commonly utilized in such system.

The burner construction of the present invention is particularly adapted for commercial size gas-fired furnaces wherein it is advantageous to have varying inputs. A common practice, for example, is to have two-stage heating. By means of the present invention it is possible to provide a gas-fired furnace with 500,000 B.t.u. input capability staged so that in actual operation the first stage fires at 250,000 B.t.u.h. input and the full rate comes on with the second stage. A cone-type burner has a limitation in that at low rate input there is excess air at the burner heat and therefore inefficient burning. In the novel burner assembly of the present invention the control 70, in the first stage, provides gas at only one of the V-shaped recesses 66, and the air mixture supplied to that one recess is proper so as to give very efiicient combustion with either natural gas LP-air mixture or with straight LP gas.

It has been found that the burner of the present invention is far less sensitive to manufacturing tolerances than prior constructions. The operational noise level has been reduced both on ignition and during combustion. The air required for combustion can be delivered at less total static air pressure than heretofore since the air ports in the plates 42 provide a great deal more free area for air flow. Fabrication of the novel burner is relatively simple and thus, there are economies in manufacture, since the burner assembly can "be made from sheet metal parts readily welded or otherwise joined to one another.

While we have described a presently preferred embodiment of the invention, it will be understood that the invention is not limited thereto, since it may be otherwise embodied within the scope of the following claims.

We claim:

1. A gas burner assembly comprising housing means defining a box-like member having substantial length and width with respect to the height thereof, perforated plate means disposed within the housing means defining a pair of adjacent generally V-shaped recesses defined by plates diverging outwardly from the housing means when viewed in section, a gas inlet opening at the apex of each V- shaped recess for supplying fuel gas to each V-shaped recess, and air inlet means in the housing means for communicating pressurized air to the perforations in said plate means for entry into said V-shaped recesses for combustion with said fuel gas.

2. A gas burner assembly as in claim 1 wherein fan means are connected directly to the housing means for supplying combustion air through the air inlet means.

3. A gas burner assembly as in claim 1 wherein control means are provided for supplying gas selectively to one or both of the gas inlet openings, the combustion process in one V-shaped recess being independent of the combustion process in the adjacent recess, resulting in near perfect combustion of the fuel gas over a wide operating range.

4. A gas burner assembly :as in claim '1 including an orifice plate adjacent each gas inlet opening substantially coextensive with the length of the V-shaped recesses for discharging gas into V-shaped recesses along the entire length thereof.

5. A gas burner assembly as in claim 4 wherein a gas distribution plate is provided in each V-shaped recess adjacent to and downstream from the orifice plate, the gas distribution plate being substantially co-extensive with the orifice plate and being spaced from the adjacent plates defining the generally V-shaped recesses for urging gas to flow outwardly from the recesses along the plates to enhance the combustion process.

References Cited UNITED STATES PATENTS 3,051,464 8/1962 Yeo et a1. 263-49 3,178,161 4/1965 Yeo et a1 263-19 M. HENSON WOOD, JR., Primary Examiner.

MICHAEL Y. MAR, Assistant Examiner.

U.S. Cl. X.R. 239556; 26319 

